Process for improving firmness of pressing die

Abstract

The invention relates to a process for improving press mold fastness. The process comprises the following steps: color fixation: putting a fabric into a dyeing machine for dyeing, taking out the dyed fabric, adding an acidic color fixing agent and a PH regulator dyeing acid DA into the dyeing machine, putting the fabric into the dyeing machine, heating to 70-80 DEG C, keeping the temperature for 30 minutes, washing with water in two jars, and taking out; soaping: adding a sodium carbonate solution, putting the fabric, heating to 50-60 DEG C, keeping the temperature for 20 minutes, and taking out washing water from the vat; post-setting: an antioxidant is added for setting, the setting temperature is 160 DEG C, and the machine speed is 25 m / min. The process disclosed by the invention can solve the problems of poor mold pressing and the like under the condition of high-temperature mold pressing requirements.

Description

Technical Field

[0001] The invention relates to the technical field of fabric dyeing and finishing, in particular to a process for improving die fastness. Background Art

[0002] The existing bra mold cup is usually made of a sponge with a certain thickness and two adhesive surface fabrics on the upper and lower surfaces, which is placed in a customized mold and pressed by the high temperature and pressure of the mold. For light-colored and white nylon-spandex underwear knitted fabrics, the fabric will oxidize and turn yellow after being pressed under high temperature and high pressure. In the past, in order to minimize the high-temperature color change of the fabric, the mold was selected as much as possible to meet the lowest temperature required for molding. However, the molding conditions of bras are becoming more and more stringent, and secondary molding is used with a molding time of up to 150-240s (pressing with sponge, the upper mold temperature of the first molding is 185, the lower mold temperature is 188, the molding time is 150S, the second molding, the upper mold temperature is 184, the lower mold temperature is 188, and the molding time is 240S). The conventional method of adding anti-yellowing agents in a fixed process after the dyeing and finishing process can no longer meet the molding level under the customer's stringent molding requirements and there is a relatively large damage to the fiber, which is irreversible and directly causes economic losses. Therefore, it is necessary to study new dyeing and finishing processes to improve the molding level of fabrics to a certain extent. Summary of the invention

[0003] The purpose of the present invention is to provide a process for improving die fastness, which can solve the problems of poor die effect and yellowing of nylon-spandex fabric under high-temperature die requirements.

[0004] To achieve the above object, the present invention provides the following technical solution: a process for improving the fastness of compression molding, the process comprising the following steps:

[0005] Step S1, color fixing: put the fabric into the dyeing machine for dyeing. After dyeing, add the acidic color fixing agent and the pH adjusting agent dyeing acid DA into the dyeing machine, heat it to 70℃-80℃ and keep it warm for 30min, wash it in two tanks and take it out;

[0006] Step S2, soap washing: add soda ash solution, raise the temperature to 50°C-60°C, keep warm for 20 minutes, and remove the washing water from the tank.

[0007] Step S3, post-setting: adding an antioxidant for setting, the setting temperature is 160° C., and the machine speed is 25 m / min.

[0008] Furthermore, the bath ratio of the color fixing in step S1 is 1:5-1:15.

[0009] Furthermore, the heating rate in step S1 is 1.5°C-2°C.

[0010] Furthermore, the mass fraction of the acidic color fixing agent is 4%, and the concentration of the pH adjusting agent dyeing acid DA is 1 g / L.

[0011] Furthermore, the bath ratio of soap washing in step S1 is 1:5-15, and the concentration of the soda ash solution is 0.5 g / L.

[0012] Furthermore, the concentration of the antioxidant is 10 g / L.

[0013] Furthermore, the step S3 of adding an antioxidant for shaping is further as follows: preparing an antioxidant solution of a certain concentration, pouring the solution into a trough of a shaping machine, passing the solution through a roller, and then shaping and drying the solution.

[0014] Beneficial effects of the present invention: Compared with the existing process, the improved process of the present invention greatly improves the compression molding effect. The original high-temperature compression molding yellowing resistance effect was only about level 2, but after the process of this application, it was improved to level 4 or even higher. The one-time production ok rate was improved. The problems of poor compression molding under the high-temperature compression molding requirements (the conditions are all sponge compression, the first compression molding upper mold temperature is 185°C, the lower mold temperature is 188°C, the compression molding time is 150S, the second compression molding, the upper mold temperature is 184°C, the lower mold temperature is 188°C, and the compression molding time is 240S) are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a comparison diagram of the molding effects of the process of the present invention and the existing process. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] See also Figure 1 The present invention provides an embodiment: a process for improving mold fastness, the process comprising the following steps:

[0018] Step S1, color fixing: putting the fabric into a dyeing machine for dyeing, after dyeing, adding an acidic color fixing agent and a pH adjusting agent, dyeing acid DA, into the dyeing machine, heating to 70°C-80°C and keeping the temperature for 30 minutes, washing with two water tanks and then taking it out; the acidic color fixing agent should not be an acidic color fixing agent, that is, an acid-free color fixing agent, because the acid-free color fixing agent is acidic itself, and after color fixing, there will be residual color fixing agent attached to the surface of the fabric, which is not easy to be washed off, resulting in a low pH on the surface of the fabric, thereby reducing the molding effect.

[0019] Step S2, soap washing: add soda ash solution, heat to 50℃-60℃, keep warm for 20min, and wash water out of the vat. Soap washing is to wash away the residual floating color on the surface of the fabric to prevent the floating color from volatilizing due to high temperature during molding. Since soda ash is used in this step, which is weakly alkaline, the pH can be adjusted during soap washing. The higher the pH, the better the molding effect.

[0020] Step S3, post-setting: adding an antioxidant for setting, the setting temperature is 160° C., and the machine speed is 25 m / min.

[0021] Color fixation is to improve the fastness of the fabric, prevent the volatilization of the dye during high-temperature molding and cause color change, and also to wash away the floating color on the surface of the fabric, while adjusting the pH and improving the molding effect.

[0022] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the bath ratio for fixing the color in step S1 is 1:5-1:15.

[0023] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the heating rate in step S1 is 1.5°C-2°C.

[0024] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the mass fraction of the acidic color fixing agent is 4%, and the concentration of the pH adjusting agent dyeing acid DA is 1 g / L.

[0025] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the bath ratio of soap washing in step S1 is 1:5-15, and the concentration of the soda ash solution is 0.5 g / L.

[0026] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the concentration of the antioxidant is 10 g / L.

[0027] Please continue reading Figure 1 As shown, in one embodiment of the present invention, the adding of antioxidant for shaping in step S3 is further as follows: preparing an antioxidant solution of a certain concentration, pouring it into a material trough of a shaping machine, passing the material through a roller, and then shaping and drying.

[0028] Example 1

[0029] A process for improving mold fastness comprises the following steps:

[0030] Prepare nylon-spandex fabric, the specific composition of the fabric is: 72% nylon and 28% spandex.

[0031] The nylon-spandex fabric is put into the dyeing vat with a bath ratio of 1:10. At room temperature, the leveling agent and dye are added in turn. The temperature is then raised to 98°C at a rate of 1.5°C / min and kept for 30 minutes. The temperature is then lowered to 80°C at a rate of 2°C / min for sampling and color matching. After confirming that there is no problem with the color, the water is drained and washed twice.

[0032] After dyeing and washing, the bath ratio is 1:10, and the temperature is raised to 75℃ at a speed of 1.5℃-2℃ for color fixation. Acidic color fixative DM-2539D (4% of the weight of the grey cloth) and pH regulator dyeing acid DA 1g / L are added, and the temperature is kept for 30 minutes. After the heat preservation is completed, the temperature is lowered to room temperature, the dye vat solution is discharged, and then 2 cold water vats are washed;

[0033] After the color fixation is completed, the bath ratio is 1:10, add 0.5g / L soda ash, raise the temperature to 55℃ at a rate of 1.5℃-2℃, keep warm for 20 minutes, cool down to room temperature, and wash out one tank of water at most, which is weakly alkaline with a pH of 7-9.

[0034] In the wet cloth state, the temperature was set at 160℃, the speed was 25m / min, 10g / L of Innovadol NY antioxidant was added, and the process requirements were met.

[0035] Comparative Example 1

[0036] The nylon-spandex fabric, dyeing and finishing method and process conditions are basically the same as those in Example 1, with the only difference being that an acidic fixing agent, i.e., an acid-free fixing agent, is directly used instead of the acidic fixing agent DM-2539D and the pH adjusting agent dyeing acid DA. After the color fixation, at least three washes are required to be taken out of the tank during soap washing.

[0037] like Figure 1 As shown, the products produced by the methods of Example 1 and Comparative Example 1 are compared. The left side of the figure is the product of Comparative Example 1, and a high temperature antioxidant is added in the post-determination process. The right side of the figure is the process of Example 1: the conditions are all sponge pressing, the upper mold temperature of the first pressing is 185°C, the lower mold temperature is 188°C, and the pressing time is 150S. The second pressing, the upper mold temperature is 184°C, the lower mold temperature is 188°C, and the pressing time is 240S. It is found that the product of the method of Example 1 has a better pressing effect than that of Comparative Example 1. The product of the method of Comparative Example 1 has a high-temperature pressing mold yellowing resistance effect of level 2, and the pressing mold yellowing is serious. The product of the method of Example 1 has a high-temperature pressing mold yellowing resistance effect of level 4, and there is basically no yellowing.

[0038] The above description is only a preferred embodiment of the present invention and should not be construed as limiting the present application. All equivalent changes and modifications made within the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A process for improving die fastness, characterized in that: The process comprises the following steps: Step S1, color fixing: put the fabric into the dyeing machine for dyeing. After dyeing, add the acidic color fixing agent and the pH adjusting agent dyeing acid DA into the dyeing machine, heat it to 70℃-80℃ and keep it warm for 30min, wash it in two tanks and take it out; Step S2, soap washing: add soda ash solution, raise the temperature to 50°C-60°C, keep warm for 20 minutes, and remove the washing water from the tank. Step S3, post-setting: adding an antioxidant for setting, the setting temperature is 160° C., and the machine speed is 25 m / min.

2. A process for improving mold fastness according to claim 1, characterized in that: The bath ratio for fixing the color in step S1 is 1:5-1:

15.

3. A process for improving mold fastness according to claim 1, characterized in that: The heating rate in step S1 is 1.5°C-2°C.

4. A process for improving mold fastness according to claim 1, characterized in that: The mass fraction of the acidic color fixing agent is 4%, and the concentration of the pH adjusting agent dyeing acid DA is 1 g / L.

5. A process for improving mold fastness according to claim 1, characterized in that: The bath ratio of soap washing in step S1 is 1:5-15, and the concentration of the soda ash solution is 0.5 g / L.

6. A process for improving mold fastness according to claim 1, characterized in that: The concentration of the antioxidant is 10 g / L.

7. A process for improving compression mold fastness according to claim 1, characterized in that: The step S3 of adding an antioxidant for shaping further comprises: preparing an antioxidant solution of a certain concentration, pouring the solution into a trough of a shaping machine, passing the solution through a roller, and then shaping and drying the solution.

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